The present invention relates to silicon carbide refractory compositions and, in particular, to silicon carbide based plastic refractories.
Plastic refractories comprise a blend of ground refractory materials and clays and occur in a plastic consistency suitable for ramming into place to form monolithic linings.
Such plastics (including silicon carbide-based plastics) are used in a variety of high temperature furnaces and metallurgical vessels, and while generally satisfactory have a number of deficiencies in certain particular uses. Specifically, such plastics are used in vessels which contain molten aluminum such as in troughs which are used to transfer molten aluminum from melters to holders, ramps in aluminum reverberatory furnaces which experience mechanical wear from charging, and other high wear areas of aluminum reverberatory furnaces such as hearths and bellyband areas. In these areas plastics do not have sufficient resistance to aluminum adhesion and penetration, thus limiting the service life of such plastics.
Moreover, due to erosion and/or aluminum metal penetration of the silicon carbide plastic, there is a contamination of the metal being processed in high wear areas of the trough or furnace. Also, the plastics do not have sufficient abrasion resistance for long term service.